Rotary-ring debarker having cablebiased springy-blade scrapers



July 15, 1958 El 0. LUNN 2,843,168 ROTARY-RING DEBARKER HAVING CABLE-BIASED SPRINGY-BLADE SCRAPERS Filed April 22, 1951 2 Sheets-Sheet 1 IN vElv'roR EDWARD O- LUNN ATTORNEY Julj 15, 1958 E. o. LUNN ROTARY-RING DEBARKER HAVING CABLE-BIASED SPRINGY-BLADE SCRAPERS 2 Sheets-Sheet 2 FiIedApril 22. 1957 INVENTOR EDWARD O. LUNN United States Patent ROTARY-RING DEBARKER HAVING CABLE- BIASED SPRINGY-BLADE SCRAPERS Edward O. Lunn, Vancouver, British Columbia, Canada Application April 22, 1957 Serial No. 654,347

11 Claims. (Cl. 144-208) My invention relates to improvements in rotary-ringtype log debarkers.

The objects of the invention are to provide a log debarker having a rotating rotor supporting bark-removing tools which advance toward a log passing through said rotor with substantially the same thrust being applied to each tool, which thrust will not vary as the tool reaches closer to the center of the rotor or as the diameter of a log becomes less.

A further object is to provide a single hydrauliccylinder device for tensioning or urging all the tools to their work, and to provide a single spring arrangement for quickly moving any tool into a depression on the bark in advance of movement imparted thereto by the hydraulic-cylinder-tensioning device, and for permitting the tool to retract from such a depression regardless of the thrust of the cylinder-tensioning device.

A further object of the invention is to provide a structure whereby the tools will all recede towards the periphery of the rotor as soon as the rotor is turning-at normal running speed, provided that the hydraulic-cylinder-tensioning device is not in operation.

Other objects will appear as the specification proceeds.

Referring to the accompanying drawings:

Figure 1 is an end elevation of the invention.

Figure 2 is a side elevation.

Figure 3 is an enlarged section through the rotort'aken on the line 3-3 of Figure 1.

Figure 4 is a section taken on the line '-4-4 of Figure 3.

Figure 5 is an end elevation of a modified arrangement for mounting the tool-tensioning cable. 7

In the drawings like characters of reference indicate corresponding parts in each figure.

The numeral -1 indicates a frame which supports a rectangular stator 2, which stator is articulated in any preferred manner to center it about any part of a log to be treated. The stator- -is provided with a bracket -4 supporting a motor 5. Rotatably mounted in the stator 2 is a cylindrical or ring-type rotor 7 which is fitted with a sprocket ring-8 adapted to be 'driven' -fr'om the motor 5 through a chain 9.

Swingingly mounted on equidistantly spaced pivot pins 11 and revolved clockwise by the rotor (as viewed in Figures 1, 4 and 5) are resilient arms 12 which preferably consist of an outwardly curved spring blade 14 which rotatably supports a grooved sheave 15 and an inwardly curved spring blade 16 having at its trailing end an inwardly bent bark-removing tool 17 which may be integral with the blade 16 or otherwise as desired. The curvature of the spring blade 14 is reversed to that of the blade 16, so that as a sheave is moved inwardly towards the center of the rotor it will exert a spring pressure upon the blade 16, assuming the tool 17 is in operating contact with a log L being fed through the rotor. As the sheave 15 is moved relatively towards the blade 16 the length of contact between said two blades will obviously increase and will thus increase the ice spring tension at the tool end of the blade 16. A pair of stops 18 and 19, see particularly Figure 4, are provided adjacent each pivot pin 11 for the purpose of limiting the movement of the arms 12 respectively in an inward and an outward direction when the machine is at rest or rotating at operating speed. If it is intended to operate the barker at speeds which are too low for centrifugal force to effectively swing the arms 12 away from the center of the rotor, said arms may be connected to an adjoining part of the rotor by suitable return springs 20'.

The stator 2 is provided on each side adjacent its top with horizontally extending brackets 21 and 22. The bracket 21 is provided with an anchor pin 23 to which a relatively strong coil spring 24 is attached and the bracket 22 supports a horizontally mounted, manually operated hydraulic cylinder 25 whose piston 26 is fitted with a pulley 27. A cable 28 is anchored to the bracket 22 as at 29 and is trained over the pulley 27 and passes in a clockwise direction as viewed in Figure 1 around the outer part of the periphery of each of the sheaves 15 and is finally connected to the left end of the tension coil spring 24.

The sheaves 15 are all provided with a cable rim 30 of sufficient width to accommodate two lays of cable 28 as said sheaves pass through the upper arc of their path of revolution with the rotor 7.

A pair of guide rollers 32 or other appropriate means may be provided on the bracket 22 to prevent the cable 28 from putting side strain on the piston 26 as the sheaves traverse the upper-quadrant of their orbit around the rotor axis.

It will be obvious that as each sheave rim passes above and below a straight line drawn between the piston 26 and the anchor pin 23 a change or flutter will occur in the tension on the sheaves 15 produced by the cable 28, which will to some extent be translated into similar tension on all the bark-removing tools. This flutter imparts an effect on each tool which, though the piston 26 exerts a constant pull on the cable 28, is intermittent as regards resistance met by the tools. In other words it is similar to the intermittent acceleration or snatching frequently produced when raking or hoeing ground manually and appears to generally increase the efiiciency' of the bark removal over that which occurs when the pull on the tool is perfectly smooth and constant.

-In the modification shown in Figure 5, a grooved segment 40 is secured to the free end of each blade 1.4 and a sheave 42 is carried by the tension spring 24 and a similar sheave 43 is carried by the free end of the piston 26. Around the grooved segments 40 and the sheaves 42 and 43 an endless cable 44 is trained for the purpose of imparting inward movement to the arms 12 to reach the bark areas of a log. Where grooved segments 40 are used, 'it will be seen that a slight slip of the cable about said segments will take place as the arms and their tools move towards and away from the log, but this slip is negligible and does not appear to affect the efiicienoy of the machine.

In operation the logs L are fed through the rotor 7 by a suitable conveyor 46 and hold-down rolls 47 or the like are provided to prevent said logs from turning while being acted upon by the bark-removing tools. The piston 26 of the hydraulic cylinder 25 is left in extended position as the machine is set in motion, so that the arms 12 are held in their outermost position by centrifugal force, thus leaving a central space between the several tools 17 to allow a log L of any suitable size to enter between said tools. As soon as the end of a log reaches the vertical plane in which the tools are carried, the operator controls the oil flow to the cylinder to tighten the cable 28 about the sheaves 15, thus moving them inwardly and causing all the bark-engaging tools 17 to move into contact with the bark or log surface. As any tool reaches a projection on an oncoming log, it will immediately cause an outward thrust on its supporting blade 16 and will stretch the tension spring 24. The first reaction to the engagement of the projection will be a slight straightening of the blades 16 and 14 and subsequently the elongation of the spring 24 and probably a slight piston movement occasioned by an incidental increase of pressure of oil in the cylinder 25.

In the example shown in Figures 1 and 2, the cable will be subject only to a slight endwise movement between the spring 24 and the piston 26 and the sheaves will rotate as they ride along the bight of the cable.

In the modification shown in Figure 5, the endless cable 44 will be running at all times that the machine is in operation and will be relatively at rest upon the segments 40.

It will, of course, be seen that sheaves may be substituted for the segments 40, if desired, without departing from the scope of the invention.

What I claim as my invention is:

1. A bark-removing machine comprising a stator, a ring-type rotor mounted for rotation within the stator, a plurality of arms pivotally mounted adjacent the periphery of the rotor and adapted to swing inwardly, a bark-removing tool carried at the free end of each arm, means carried by each arm and having a cable-receiving rim, a cable extending across the stator in the path of the cable rims as said rims travel around with the rotor, said cable passing around the cable rims, and manually operable means for contracting a bight of the cable around the rims to move said bark-removing tools into engagement with a log being fed through the rotor.

2. A bark-removing machine as claimed in claim 1, and spring means for automatically tensioning the cable when it is being contracted by the manually operable means.

3. A bark-removing machine as claimed in claim 1, said automatic means for contracting the cable about the cable rims being a hydraulic cylinder.

4. A bark-removing machine as claimed in claim 1, wherein each arm consists of a resilient blade pivotally mounted to the rotor and having a bark-removing tool at the opposite end and spring means for connecting the cable rim to the blade.

5. A bark-removing machine as claimed in claim 1, wherein each arm consists of an inwardly curved blade and an outwardly curved blade, one of said blades supporting the bark-removing tool and the second of said blades supporting the cable rim.

6. A bark-removing machine as claimed in claim 1., wherein the cable is an endless cable and the return ends of the cable are trained over sheaves, one of which sheaves is mounted for movement towards and away from the other of said sheaves.

7. A bark-removing machine as claimed in claim 1, and spring means normally urging the arms away from the center of the rotor.

8. A bark-removing machine comprising a stator, a ring-type rotor mounted for rotation within the stator, a plurality of arms pivotally mounted adjacent the periphery of the rotor and adapted to swing inwardly, a bark-removing tool carried at the free end of each arm, means carried by each arm and having a cable-receiving rim, a cable extending across the stator in the path of the cable rims as said rims travel around with the rotor, said cable passing around the cable rims, and manually operable means for contracting a bight of the cable around the rims to move said bark-removing tools into engagement with a log being fed through the rotor, each arm consisting of an inwardly curved blade and an outwardly curved blade, one of said blades supporting the barkremoving tool and the second of said blades supporting the cable rim, said blades having their convex faces facing each other.

9. A bark-removing machine comprising a stator, a ring-type rotor mounted for rotation within the stator, a plurality of arms pivotally mounted adjacent the periphery of the rotor and adapted to be urged inwardly, a barkremoving tool carried at the free end of each arm, a sheave freely journaled upon the arm, said sheaves of the arms having their grooves disposed in a plane normal to the axis of the rotor, a cable having one part anchored adjacent one side of the stator and another part mounted for endwise movement towards and away from the anchored part of said cable and supported adjacent the opposite side of the stator, an intermediate portion of said cable being trained around the outer portion of each of the sheaves, and manually operated means for moving the second named part to contract the cable about the sheaves and urge the tool into bark-removing engagement with a log.

10. A bark-removing machine as claimed in claim 9, wherein the normal path of the sheaves in their orbital path around the center of the rotor will cut an imaginary line drawn between the anchored part of the cable and the point where said cable extends in supported position at the opposite side of the stator.

11. A bark-removing machine as claimed in claim 9, wherein the cable is an endless cable and the return ends of the cable are trained over sheaves, one of which sheaves is mounted for movement towards and away from the other of said sheaves and wherein the secondmentioned sheave is spring-tensioned away from the firstmentioned sheave.

References Cited in the file of this patent UNITED STATES PATENTS 1,887,908 Tidblad Nov. 15, 1932 2,774,397 Letfier Dec. 18, 1956 2,786,499 Brundell et al. Mar. 26, 1957 2,787,304 Brundell et al. Apr. 2, 1957 FOREIGN PATENTS 87,883 Norway Aug. 13, 1956 

